JP5730133B2 - DC power supply - Google Patents

Description

  The present invention relates to a DC power supply apparatus that supplies DC power to equipment.

  For example, in information communication facilities such as IDS (Internet Data Center) where various computers (mainframes, servers, etc.) and data communication devices are installed and operated, a power supply system for supplying power from the power supply device to each device is provided. It is done. As such a power supply system, an AC power supply system using an AC power supply apparatus is generally employed.

  In an information communication facility, the power consumption may fluctuate greatly in an instant due to, for example, an inrush current at the start-up of the device or a rapid change in the processing load of the device. Therefore, it is necessary for the power supply system to have a configuration capable of supplying an amount of power that can cope with such a maximum peak of instantaneous power consumption. However, the average value of power consumption in information communication facilities is often much smaller than the maximum peak power value. In other words, the conventional power supply system needs to be configured to be able to supply much more power than is necessary in order to cope with the maximum peak of instantaneous power consumption, and the power supply device is larger than necessary. There arises a problem that it is converted to

  As an example of a conventional technique for solving such a problem, an AC power supply system including an AC peak cut power supply device is known (see, for example, Patent Document 1). This AC peak cut power supply device supplies commercial AC power to a load device, converts commercial AC power into DC power by an inverter, and charges the storage battery. When the load current increases instantaneously, in addition to the commercial AC power, DC power stored in the storage battery is further converted into AC power by the inverter and supplied to the load device. Switching between charging and discharging of the storage battery is performed by adjusting the phase of the induced voltage of the inverter with respect to the phase of the commercial AC power. According to the related art, in the AC power supply system, it is possible to greatly reduce the size of the AC power supply apparatus while accommodating an instantaneous increase in power consumption.

JP-A-4-178807

  In an AC power feeding system generally employed in information communication equipment, commercial AC power is first converted to DC power and charged to a UPS (uninterruptible power supply system) battery of the information communication equipment. The DC power is converted to AC power of AC 100 to 200 V and distributed to each device. Each device converts the distributed AC power into DC power, and further converts the DC power into DC power having a desired voltage. That is, in the AC power supply system, since power conversion is required four times in total, there is a problem that power loss due to power conversion is large.

  In recent years, in order to reduce power consumption in information communication facilities, a direct current power supply system using high voltage direct current power supply (HVDC) technology has been attracting attention. Since the DC power supply system converts commercial AC power to DC power and then distributes the DC power to each device as it is, the number of power conversions is only two. That is, since the DC power supply system can reduce the number of times of power conversion as compared with the AC power supply system, the loss during power conversion can be reduced and the power use efficiency can be improved.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the size of a DC power supply apparatus while accommodating an instantaneous increase in power consumption in a DC power supply system.

<First Aspect of the Present Invention>
According to a first aspect of the present invention, there is provided a power converter that converts commercial AC power into DC power, a charging circuit that charges the storage battery with DC power output from the power converter, and the voltage of the storage battery is set to an arbitrary voltage. A DC voltage converter that converts and outputs, a diode OR circuit that combines and outputs DC power output from the power converter and DC power output from the DC voltage converter, and the power converter outputs In a state where the amount of DC power per unit time is less than or equal to the allowable power amount, the output voltage of the DC voltage converter is set to a voltage lower than the output voltage of the power converter, and the DC output from the power converter A control device that sets the output voltage of the DC voltage converter to a voltage equal to or higher than the output voltage of the power converter when the amount of power per unit time exceeds the allowable power amount; A DC power supply apparatus comprising a.

  Here, the allowable power amount is the rating of the amount of power that can be supplied by the power converter, that is, the maximum amount of power per unit time that the power converter can supply at the rated voltage, or the rating of commercial AC power, that is, commercial power. It means the maximum amount of power per unit time that AC power can be supplied at the rated voltage.

  In a state where the amount of DC power output by the power conversion device per unit time is equal to or less than the allowable power amount, it is possible to sufficiently supply power to the load device using only the DC power output from the power conversion device. In this state, the control device sets the output voltage of the DC voltage converter to a voltage lower than the output voltage of the power converter. The DC power output from the power converter and the DC power output from the DC voltage converter are combined and output by a diode OR circuit. Therefore, in the DC power supply device, the DC power output from the power conversion device is supplied to the load device via the diode OR circuit, and the power stored in the storage battery is hardly supplied to the load device.

  On the other hand, in a state in which the amount of DC power output by the power conversion device per unit time exceeds the allowable power amount, the DC power output from the power conversion device alone can sufficiently supply power to the load device. The possibility of not being possible arises. In this state, the control device sets the output voltage of the DC voltage converter to a voltage equal to or higher than the output voltage of the power converter. As a result, in addition to the DC power output from the power conversion device, the DC power supply device further supplies DC power output from the DC voltage conversion device (power stored in advance in the storage battery) to the load device via the diode OR circuit. It becomes a state.

  That is, the DC power supply device according to the present invention is in a state where the power supply to the load device cannot be sufficiently performed only by the DC power output by the power converter due to the instantaneous maximum power consumption peak generated in the load device. The insufficient power can be supplied from the storage battery. As a result, the DC power supply device can be prevented from becoming larger than necessary while flexibly responding to the maximum peak of instantaneous power consumption.

  As a result, according to the first aspect of the present invention, in the DC power supply system, it is possible to obtain an effect that the DC power supply apparatus can be reduced in size while accommodating an instantaneous increase in power consumption.

<Second Aspect of the Present Invention>
According to a second aspect of the present invention, in the first aspect of the present invention described above, the power converter further includes a voltage detection circuit that detects a voltage of DC power output from the power converter, and the control device includes the power converter. On the condition that the voltage of the DC power output by the power converter is higher than a voltage threshold, it is determined that the amount of power per unit time of the DC power output by the power converter is less than or equal to the allowable power, and the power converter It is determined that the amount of DC power output per unit time of the DC power output by the power converter exceeds the allowable power amount on condition that the voltage of DC power to be output is equal to or lower than the voltage threshold value. The DC power supply device.

  When the amount of DC power output by the power conversion device per unit time increases beyond the allowable power amount, the voltage of the DC power output by the power conversion device decreases accordingly. . Therefore, it is determined that the amount of DC power output per unit time of the DC power output from the power converter exceeds the allowable power on condition that the voltage of the DC power output from the power converter falls below the voltage threshold. be able to. This voltage threshold is the DC power output from the DC power supply device from the lowest voltage at which the load device can operate stably from the viewpoint of maintaining the state in which the load device supplied with power from the DC power supply device operates stably. Any voltage can be set within the rated voltage range.

<Third Aspect of the Present Invention>
According to a third aspect of the present invention, in the first aspect of the present invention described above, the power converter further includes a current detection circuit that detects a current of DC power output from the power converter, and the control device includes the power converter. On the condition that the current of the DC power output by the power converter is smaller than the current threshold, it is determined that the power amount per unit time of the DC power output by the power converter is less than or equal to the allowable power amount, and the power converter It is determined that the amount of DC power output per unit time of the DC power output by the power converter exceeds the allowable power, on condition that the current of DC power to be output is equal to or greater than the current threshold. The DC power supply device.

  As the amount of power per unit time of DC power output from the power converter increases, the current of DC power output from the power converter also increases accordingly. Therefore, on the condition that the current of the DC power output from the power converter flows more than a certain current value, the power per unit time of the DC power output from the power converter exceeds the allowable power. Can be determined. The current threshold value as the constant current value can be derived, for example, from the relationship between the rated voltage of the DC power output from the power converter and the allowable power amount. In other words, the current threshold is set such that, for example, the amount of DC power output by the power conversion device per unit time is the allowable power amount from the viewpoint of maintaining a state in which the load device supplied with power from the DC power supply device operates stably. The current value in the reached state may be set to an arbitrary value as a guide.

<Fourth aspect of the present invention>
According to a fourth aspect of the present invention, in the first aspect of the present invention described above, a voltage detection circuit that detects a voltage of DC power output from the power converter, and a current of DC power output from the power converter. And a current detection circuit for detecting DC current per unit time of the DC power output by the power converter based on the voltage detected by the voltage detection circuit and the current detected by the current detection circuit. The DC power supply device is characterized in that the amount of electric power is calculated.

  According to such a feature, the voltage and current of the DC power output from the power converter are measured, and the amount of power per unit time is calculated from the measured value, so that the DC power output from the power converter is calculated. The amount of power per unit time can be specified with high accuracy. Therefore, it is possible to specify with high accuracy whether or not the amount of DC power output per unit time of the DC power output from the power converter exceeds the allowable power amount. As a result, the output voltage of the direct-current voltage converter can be controlled with higher accuracy, so that it is possible to further reduce the possibility of a state where the power supplied to the load device is insufficient.

<Fifth aspect of the present invention>
According to a fifth aspect of the present invention, in the first aspect of the present invention described above, the power conversion device further includes a power detection circuit that detects a power amount per unit time of DC power output from the power converter. DC power supply device.

  According to such a feature, since the power amount per unit time of the DC power output from the power converter is measured by the power detection circuit, the power amount per unit time can be specified with high accuracy. Therefore, it is possible to specify with high accuracy whether or not the amount of DC power output per unit time of the DC power output from the power converter exceeds the allowable power amount. As a result, the output voltage of the direct-current voltage converter can be controlled with higher accuracy, so that the possibility of a state where the power supplied to the load device is insufficient can be reduced. Moreover, according to the said characteristic, since it is not necessary to calculate and obtain | require the electric energy per unit time of the direct-current power which a power converter device outputs with a control apparatus, the processing load of a control apparatus can be reduced.

<Sixth aspect of the present invention>
According to a sixth aspect of the present invention, in any one of the first to fifth aspects of the present invention described above, the output impedance of the DC voltage converter is set lower than the output impedance of the power converter. Is a DC power supply device characterized by
According to such a feature, in a state where the output voltage of the DC voltage conversion device is set to a voltage equal to or higher than the output voltage of the power conversion device, more DC power can be supplied from the storage battery. It is possible to respond more flexibly and surely to an increase in power consumption.

  According to the present invention, in the DC power supply system, it is possible to obtain an effect that the DC power supply apparatus can be reduced in size while accommodating an instantaneous increase in power consumption.

1 is an overall configuration diagram of a DC power supply device according to the present invention. The flowchart which illustrated 1st Example of the electric power control by a control apparatus. The flowchart which illustrated 2nd Example of the electric power control by a control apparatus. The flowchart which illustrated the 3rd Example of the power control by a control apparatus. The timing chart which illustrated the change of the output voltage and output current of PSU and BBU. The graph which illustrated the change to the time axis of the electric energy which a direct-current power feeder supplies.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Configuration of DC power supply device>
The configuration of the DC power supply device according to the present invention will be described with reference to FIG.
FIG. 1 is an overall configuration diagram of the DC power supply device 100.

  A DC power supply device 100 according to the present invention includes a PSU (Power Supply Unit) 10, a BBU (Battery Backup Unit) 20, a diode OR circuit 30, a power detection circuit 40, and a PDU (Power Distribution Unit) 50.

  The PSU 10 as a “power converter” is a device that converts commercial AC power (for example, AC 200 V) into DC power, and includes a filter circuit 11, a rectifying / smoothing circuit 12, and a switching circuit 13. The filter circuit 11 removes a noise component contained in the supplied commercial AC power. The rectifying / smoothing circuit 12 rectifies and smoothes commercial AC power that has passed through the filter circuit 11 and converts the commercial AC power into DC power. The switching circuit 13 includes a step-up chopper circuit, for example, and boosts the voltage of the DC power output from the rectifying and smoothing circuit 12 to convert it to a rated voltage (for example, DC 250V to 400V).

  The BBU 20 includes a charging circuit 21, a storage battery 22, a DC / DC converter 23, and a control device 24. The charging circuit 21 is a circuit that charges the storage battery 22 with DC power output from the PSU 10, and is controlled by the control device 24. The storage battery 22 is, for example, a nickel hydride secondary battery or a lithium ion secondary battery. The DC / DC converter 23 as a “DC voltage converter” converts the voltage of the storage battery 22 into an arbitrary voltage and outputs it. The control device 24 is a so-called microcomputer control device or PLC (Programmable Logic Controller), and includes a CPU (Central Processing Unit) that executes a control program stored in advance.

  The diode OR circuit 30 includes two diodes D1 and D2. The anode terminal of the diode D <b> 1 is connected to the output terminal of the switching circuit 13. The anode terminal of the diode D 2 is connected to the output terminal of the DC / DC converter 23. The cathode terminal of the diode D1 is connected to the cathode terminal of the diode D2, and this connection point is connected to the PDU 50. That is, the diode OR circuit 30 combines the DC power output from the PSU 10 (DC power output from the switching circuit 13) and the DC power output from the BBU 20 (DC power output from the DC / DC converter 23) and outputs the resultant to the PDU 50. Circuit. For example, when a so-called instantaneous power failure occurs in commercial AC power, the power supply from the PSU 10 is stopped during the instantaneous power failure, but the power supply to the load device is maintained by the power supply from the BBU 20.

  The power detection circuit 40 includes a current detection transformer (current transformer) CT, two resistors R1 and R2, and an A / D converter 41. The current detection transformer CT as the “current detection circuit” is connected in series to the output line of the PSU 10 and detects the current of the DC power output from the PSU 10. The output terminal of the current detection transformer CT is connected to the input port of the control device 24. As this “current detection circuit”, for example, a shunt resistor can be used in addition to the current detection transformer CT. The resistors R1 and R2 and the A / D converter 41 constitute a “voltage detection circuit” that detects the voltage of the DC power output from the PSU 10. One end of the resistor R1 is connected to the output terminal of the switching circuit 13. The other end side of the resistor R1 is connected to one end side of the resistor R2. The other end side of the resistor R2 is connected to the ground. A connection point between the resistors R1 and R2 is connected to an input terminal of the A / D converter 41. The output terminal of the A / D converter 41 is connected to the input port of the control device 24. The voltage of the DC power output from the PSU 10 is divided by a voltage dividing ratio corresponding to the resistance ratio between the resistors R1 and R2, converted into a digital signal by the A / D converter 41, and output to the control device 24.

  The PDU 50 is a device that distributes the DC power output from the diode OR circuit 30 to a plurality of load devices (not shown).

<First Example of Power Control by Control Device 24>
A first embodiment of power control by the control device 24 will be described with reference to FIGS. 2, 5, and 6.
In this embodiment, it is not necessary to provide a “current detection circuit” (current detection transformer CT, shunt resistor, etc.) for detecting the current of the DC power output from the PSU 10.

FIG. 2 is a flowchart illustrating a first embodiment of power control by the control device 24. The control procedure illustrated in the flowchart is a procedure that is repeatedly executed at regular intervals.
FIG. 5 is a timing chart illustrating changes in voltage and current of DC power output from the PSU 10 and DC power output from the BBU 20. FIG. 5A is a voltage change, and FIG. 5B is a current change. Are respectively illustrated. FIG. 6 is a graph illustrating changes in the amount of power supplied by the DC power supply apparatus 100 with respect to the time axis.

  First, a DC power voltage V1 output from the PSU 10 (hereinafter referred to as “PSU voltage V1”) is calculated from a signal output from the A / D converter 41, and it is determined whether or not the PSU voltage V1 is higher than a voltage threshold Vt. (Step S1). Here, the voltage threshold Vt is determined by the DC power supply device 100 from the lowest voltage at which the load device can stably operate from the viewpoint of maintaining a state in which the load device supplied with power from the DC power supply device 100 operates stably. What is necessary is just to set to arbitrary voltage within the range of the rated voltage of the direct-current power to output.

  When the PSU voltage V1 is higher than the voltage threshold Vt (Yes in step S1), the power amount P1 per unit time of DC power output from the PSU 10 (hereinafter referred to as “PSU power amount P1”) is the allowable power amount Pt. It is determined that the state is as follows. Here, the allowable power amount Pt is the rating of the amount of power that can be supplied by the PSU 10, that is, the maximum amount of power per unit time that the PSU 10 can supply at the rated voltage, or the rating of commercial AC power, that is, the commercial AC power. It means the maximum amount of power per unit time that can be supplied at the rated voltage.

  In a state where the PSU power amount P1 is equal to or less than the allowable power amount Pt, it is possible to sufficiently supply power to the load device using only the DC power output from the PSU 10. Therefore, when the PSU voltage V1 is higher than the voltage threshold Vt (Yes in step S1), the output voltage V2 of the DC / DC converter 23 of the BBU 20 (hereinafter referred to as “BBU voltage V2”) is set to a voltage lower than the PSU voltage V1. Set (step S2). As a result, the DC power supply apparatus 100 is in a state where the DC power output from the PSU 10 is supplied to the load device via the diode OR circuit 30 and the power stored in the storage battery 22 is hardly supplied to the load device.

  On the other hand, when the PSU power amount P1 increases beyond the allowable power amount Pt, the PSU voltage V1 decreases accordingly (timing T1 in FIG. 5). Therefore, when the PSU voltage V1 is equal to or lower than the voltage threshold Vt (No in step S1), it is determined that the PSU power amount P1 exceeds the allowable power amount Pt (timing T2 in FIG. 5).

  In a state where the PSU power amount P1 exceeds the allowable power amount Pt, there is a possibility that the power supply to the load device cannot be sufficiently performed only by the DC power output from the PSU 10. Therefore, when the PSU voltage V1 is equal to or lower than the voltage threshold Vt (No in step S1), the BBU voltage V2 is set to a voltage equal to or higher than the PSU voltage V1 (step S3). As a result, in a state where the PSU power amount P1 exceeds the allowable power amount Pt, in addition to the PSU power amount P1, DC power output from the DC / DC converter 23 of the BBU 20 (power stored in the storage battery 22 in advance) is further increased. The power amount P2 per unit time (hereinafter referred to as “BBU power amount P2”) is supplied to the load device via the diode OR circuit 30 (FIG. 6).

  At this time, the BBU voltage V2 is set so that the power shortage of the PSU power amount P1 is supplied from the BBU 20 as the BBU power amount P2. More specifically, for example, based on the PSU voltage V1, the output impedance of the PSU 10 (the output impedance of the switching circuit 13), the output impedance of the BBU 20 (the output impedance of the DC / DC converter 23), etc., the PSU power amount P1 and the BBU power The BBU voltage V2 may be set so that the amount P2 has a desired ratio.

  As a configuration of the DC power supply device 100, it is preferable that the output impedance of the BBU 20 (the output impedance of the DC / DC converter 23) is set lower than the output impedance of the PSU 10 (the output impedance of the switching circuit 13). As a result, in a state where the BBU voltage V2 is set to a voltage equal to or higher than the PSU voltage V1, it becomes possible to supply more DC power from the storage battery 22, so that it is more flexible and reliable with respect to an instantaneous increase in power consumption. It can correspond to. Furthermore, as a configuration of the DC power supply device 100, it is preferable that an output impedance control circuit is provided in the DC / DC converter 23 so that the control device 24 can increase or decrease the output impedance of the DC / DC converter 23. As a result, the ratio between the PSU power amount P1 and the BBU power amount P2 can be set more flexibly and with high accuracy.

  As described above, the DC power supply apparatus 100 according to the present invention can sufficiently supply power to the load device with only the DC power output from the PSU 10 due to the instantaneous maximum power consumption peak generated in the load device. In an incapable state, the insufficient power can be supplied from the storage battery 22. As a result, the DC power supply device 100 can be prevented from becoming larger than necessary while flexibly responding to the maximum peak of instantaneous power consumption.

  As described above, according to the present invention, in the DC power supply system, the DC power supply apparatus 100 can be downsized while accommodating an instantaneous increase in power consumption.

<Second Example of Power Control by Control Device 24>
A second embodiment of power control by the control device 24 will be described with reference to FIGS. 3, 5, and 6. FIG.
In this embodiment, it is not necessary to provide a “voltage detection circuit” (resistors R1, R2, A / D converter 41, etc.) for detecting the voltage of the DC power output from the PSU 10.

  FIG. 3 is a flowchart illustrating a second embodiment of power control by the control device 24. The control procedure illustrated in the flowchart is a procedure that is repeatedly executed at regular intervals.

  First, a DC power current I1 output from the PSU 10 (hereinafter referred to as “PSU current I1”) is calculated from a signal output from the current detection transformer CT, and it is determined whether or not the PSU current I1 is smaller than the current threshold It. (Step S11). Here, the current threshold It can be derived from, for example, the relationship between the rated voltage of the DC power output from the PSU 10 and the allowable power amount Pt. In other words, the current threshold It is an arbitrary value based on the current value in a state in which the PSU power amount P1 reaches the allowable power amount Pt, for example, from the viewpoint of maintaining a state in which the load device supplied with power from the PSU 10 operates stably. Set it to a value.

  When the PSU current I1 is smaller than the current threshold It (Yes in step S11), it is determined that the PSU power amount P1 is equal to or less than the allowable power amount Pt. In a state where the PSU power amount P1 is equal to or less than the allowable power amount Pt, it is possible to sufficiently supply power to the load device using only the DC power output from the PSU 10. Therefore, when the PSU current I1 is smaller than the current threshold It (Yes in step S11), the BBU voltage V2 is set to a voltage lower than the PSU voltage V1 (step S12). As a result, the DC power supply apparatus 100 is in a state where the DC power output from the PSU 10 is supplied to the load device via the diode OR circuit 30 and the power stored in the storage battery 22 is hardly supplied to the load device.

  On the other hand, as the PSU power amount P1 increases, the PSU current I1 also increases accordingly (FIG. 5 (b)). Therefore, when the PSU current I1 flows more than the current threshold It (No in step S11), it is determined that the PSU power amount P1 exceeds the allowable power amount Pt (timing T2 in FIG. 5).

  In a state where the PSU power amount P1 exceeds the allowable power amount Pt, there is a possibility that the power supply to the load device cannot be sufficiently performed only by the DC power output from the PSU 10. Therefore, when the PSU current I1 flows over the current threshold It (No in step S11), the BBU voltage V2 is set to a voltage equal to or higher than the PSU voltage V1 (step S13). As a result, in addition to the PSU current I1, a current I2 from the DC / DC converter 23 of the BBU 20 (hereinafter referred to as “BBU current I2”) flows through the load device (FIG. 5B). That is, when the PSU power amount P1 exceeds the allowable power amount Pt, in addition to the PSU power amount P1, the BBU power amount P2 is further supplied to the load device via the diode OR circuit 30 (FIG. 6). ).

  Even in such an embodiment, the present invention can be implemented, and the same effects as those of the first embodiment can be obtained.

<Third embodiment of power control by control device 24>
A third embodiment of power control by the control device 24 will be described with reference to FIGS.
FIG. 4 is a flowchart illustrating a third embodiment of power control by the control device 24. The control procedure illustrated in the flowchart is a procedure that is repeatedly executed at regular intervals.

  First, the PSU voltage V1 is calculated from the signal output from the A / D converter 41, the PSU current I1 is calculated from the signal output from the current detection transformer CT, and the PSU power amount P1 is calculated based on the PSU voltage V1 and the PSU current I1. Is calculated (step S21). Subsequently, it is determined whether or not the PSU power amount P1 obtained by calculation is equal to or less than the allowable power amount Pt (step S22).

  When the PSU power amount P1 is equal to or less than the allowable power amount Pt (Yes in step S22), the power supply to the load device can be sufficiently performed only by the DC power output from the PSU 10, and therefore the BBU voltage V2 is set to PSU. A voltage lower than the voltage V1 is set (step S23). As a result, the DC power supply apparatus 100 is in a state where the DC power output from the PSU 10 is supplied to the load device via the diode OR circuit 30 and the power stored in the storage battery 22 is hardly supplied to the load device.

  On the other hand, when the PSU power amount P1 exceeds the allowable power amount Pt (No in step S22), there is a possibility that the power supply to the load device cannot be sufficiently performed only by the DC power output from the PSU 10. Therefore, the BBU voltage V2 is set to a voltage equal to or higher than the PSU voltage V1 (step S24). As a result, in a state where the PSU power amount P1 exceeds the allowable power amount Pt, in addition to the PSU power amount P1, the BBU power amount P2 is further supplied to the load device via the diode OR circuit 30 (FIG. 6).

  Even in such an embodiment, the present invention can be implemented, and the same effects as those of the first embodiment can be obtained. In the third embodiment, since the PSU power amount P1 is calculated from the actually measured PSU voltage V1 and the PSU current I1, the PSU power amount P1 can be specified with high accuracy. Therefore, it is possible to specify with high accuracy whether or not the PSU power amount P1 exceeds the allowable power amount Pt. As a result, the output voltage of the DC / DC converter 23 of the BBU 20 can be controlled with higher accuracy, so that it is possible to further reduce the possibility that the power supplied to the load device will be insufficient.

<Other embodiments and modifications>
The present invention is not particularly limited to the embodiments described above, and it goes without saying that various modifications are possible within the scope of the invention described in the claims.

  For example, in the third embodiment, the power detection circuit 40 may use a power meter or the like that measures and detects the PSU power amount P1 instead of the current detection transformer CT, the resistor R1, the resistor R2, and the A / D converter 41. Good. Even in such an aspect, the present invention can be implemented, and it is not necessary to calculate and obtain the PSU power amount P1 by the control device 24. Therefore, the processing load of the control device 24 can be reduced.

  A control program for causing a computer to execute the control procedure of the first to third embodiments (the procedure of the flowcharts shown in FIGS. 2 to 4) and a storage medium storing the control program can also be the subject of the present invention.

10 PSU (Power Supply Unit)
11 Filter Circuit 12 Rectifier Smoothing Circuit 13 Switching Circuit 20 BBU (Battery Backup Unit)
21 Charging circuit 22 Storage battery 23 DC / DC converter 24 Control device 30 Diode OR circuit 40 Power detection circuit 41 AC / DC converter 50 PDU (Power Distribution Unit)
100 DC power supply CT Current detection transformer

Claims (6)

A power converter for converting commercial AC power into DC power;
A charging circuit for charging a storage battery with DC power output by the power converter;
A DC voltage converter for converting the voltage of the storage battery into an arbitrary voltage and outputting the voltage;
A diode OR circuit that synthesizes and outputs DC power output from the power converter and DC power output from the DC voltage converter;
In a state where the power amount per unit time of DC power output by the power converter is less than or equal to an allowable power amount, the output voltage of the DC voltage converter is set to a voltage lower than the output voltage of the power converter, A control device that sets the output voltage of the DC voltage conversion device to a voltage equal to or higher than the output voltage of the power conversion device when the amount of DC power output by the power conversion device per unit time exceeds the allowable power amount and, with a,
The DC power supply device , wherein an output impedance of the DC voltage converter is set lower than an output impedance of the power converter . 2. The DC power supply apparatus according to claim 1, further comprising an output impedance control circuit that adjusts an output impedance of the DC voltage converter. The DC power supply device according to claim 1 or 2 , further comprising a voltage detection circuit that detects a voltage of DC power output by the power conversion device,
The control device is in a state in which the amount of power per unit time of the DC power output from the power converter is less than or equal to the allowable power on condition that the voltage of the DC power output from the power converter is higher than a voltage threshold. The power amount per unit time of the DC power output from the power converter exceeds the allowable power on the condition that the voltage of the DC power output from the power converter is equal to or less than the voltage threshold. A DC power supply device, characterized in that it is determined to be in a state of being present. The DC power supply device according to claim 1 , further comprising a current detection circuit that detects a current of DC power output by the power conversion device,
The control device is in a state where the amount of power per unit time of the DC power output from the power converter is less than or equal to the allowable power on condition that the current of the DC power output from the power converter is smaller than a current threshold. The power amount per unit time of the DC power output from the power converter exceeds the allowable power on the condition that the current of the DC power output from the power converter is equal to or greater than the current threshold. A DC power supply device, characterized in that it is determined to be in a state of being present. The DC power supply device according to claim 1 or 2 , wherein a voltage detection circuit that detects a voltage of DC power output from the power conversion device, and a current detection circuit that detects a current of DC power output from the power conversion device; Further comprising
The control device calculates a power amount per unit time of DC power output from the power converter based on a voltage detected by the voltage detection circuit and a current detected by the current detection circuit. DC power supply device. 3. The DC power supply apparatus according to claim 1 , further comprising a power detection circuit that detects an amount of power per unit time of DC power output from the power conversion apparatus.

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